When your server is slow to answer, TTFB (Time To First Byte — the wait before anything arrives) climbs, and that drags LCP with it. Two tools help, differently. A CDN (Content Delivery Network) copies your site to servers near each visitor. Caching saves a finished page so the server skips rebuilding it.
Think of a CDN as opening branches in many cities, and caching as keeping meals pre-cooked.
When each helps most:
— Visitors far from your server: a CDN cuts the travel distance.
— A slow database or heavy page build: caching skips the slow work.
Try this: measure TTFB in PageSpeed Insights. If it's high but visitors are nearby, caching is your fix first. If they're worldwide, add a CDN. Match the tool to the real cause.
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A CDN vs caching: which fixes slow TTFB?
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